In the manufacturing process of a semiconductor device or the like, there has been a process of forming an electrode by forming a trench and hole-shaped groove (for example, a contact hole or a line-and-space) in an interlayer insulating film on a silicon substrate, and by embedding a silicon film (Si film) such as a polysilicon film, an amorphous silicon film, and a polysilicon film and an amorphous silicon film doped with impurities.
In such a process, for example, there has been a method of forming a contact hole in the interlayer insulating film on the silicon substrate, forming the polysilicon layer using a CVD (Chemical Vapor Deposition) method, and forming the polysilicon film again after slight etching of the polysilicon film.
However, when a surface roughness of the silicon film is degraded in the etching process after forming the silicon film, the silicon film cannot be properly embedded, which may result in a degradation of characteristics as an electrode of the Si film. Furthermore, this problem remarkably arises particularly in the case of using a silicon film doped with phosphorus (P).